Ballmer has signed a binding agreement with the Sterling Family Trust, but the deal must be approved by the NBA. Shelly Sterling has negotiated the sale of the franchise after her husband, Donald Sterling, was banned by the NBA for making racist remarks.

The NBA has scheduled a meeting for next Tuesday when a vote is due to take place on whether to force the sale of the franchise.

The takeover also needs to be rubber-stamped by Donald Sterling, and his attorney Bobby Samini told the Associated Press news agency yesterday (Thursday): ‘Sterling is not selling the team. That’s his position.’ To add to the confusion, a May 22 letter from one of Sterling’s attorneys has emerged, stating that he had authorised his wife to broker the sale of the Clippers.

However, Samini said that Sterling had changed his mind since then, after NBA commissioner Adam Silver acted as ‘judge, jury and executioner’ by banning Sterling, fining him $2.5m and trying to oust him as the Clippers’ owner.

Ballmer clinched the deal with Shelly Sterling after visiting her Malibu home to make a personal presentation to overcome rival bids by Guggenheim Partners and a group including former NBA All-Star Grant Hill.

Ballmer would appear to have presented the most attractive offer, not only because the bid was more lucrative than the others on the table, but also because he was not part of a consortium, paving the way for a more straightforward deal.

Ballmer and investor Chris Hansen headed a group that agreed to a deal to buy the NBA’s Sacramento Kings from the Maloof family in January 2013, but the takeover fell through after the franchise’s owners resisted attempts to move the team to Seattle. There is no prospect of the Clippers being moved from Los Angeles.